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AR# 8762

Description

General Description:

What are the I/O switching levels during EXTEST (boundary scan interconnect testing)?

Solution

For unconfigured devices, I/Os will drive rail-rail between Ground and the voltage level on the VCCO pin in that bank. If the VCCO pin for that bank is at 3.3V, the I/O will drive at LVTTL levels, a 12mA drive strength, and a slow slew rate.

When sensing voltage levels applied to the pin during EXTEST or SAMPLE/PRELOAD, Vih=2.0V.

For configured devices, IOBs will retain their user configuration during boundary scan testing. For example, if an IOB is configured for GTL+, the IOB will drive and sense at GTL+ levels.